Air purification system

The invention discloses an air purification system, and belongs to the technical field of air purification equipment, the air purification system comprises a front filter device, a rear filter device and a catalytic device used for treating harmful gas, the front filter device is connected with the catalytic device through a heat exchange pipeline and a heating pipeline which are connected in parallel; the heat exchange pipeline is provided with a heat exchanger communicated with an engine waste gas exhaust port, the heating pipeline is provided with a heater, and the catalytic device is connected with the rear filtering device through a cooler. The heat exchanger connected with the engine waste gas exhaust port is arranged on the heat exchange pipeline between the catalytic device and the front filter device, so that the heat of engine waste gas can be used for heating air, the catalytic conditions of catalytic equipment are met, and extra energy consumption is reduced; meanwhile, a heating pipeline connecte